Polish shale gas extraction may be relatively low, based on exploration works and tests on deposits conducted so far, fuels group PKN Orlen said on its website.

"Geological characteristics of the Polish shale rock as well as the results of the exploration works and tests conducted on the deposits so far indicate clearly that the average estimated gas extraction from the shale formations analyzed so far in Poland may be on a relatively low level," the statement reads.

The profitability of shale gas E&E activities in Poland is also strongly influenced by the high exploration costs, which partly result from the considerable depth of the deposit location as well as limited geological information base for the region, Orlen said.

Polish geological conditions make it impossible to directly transfer shale gas E&E technologies used by companies in the US, Orlen Upstream CEO Wieslaw Prugar said in a comment.

"The results of exploration works carried out by operators since 2009 confirm that Polish geological conditions differ significantly from those in the North American shale basins and are much more difficult," Prugar said. "We are giving up universal and widely described practices in order to prepare novel methods for effectively making available unconventional deposits."